Shotguns
rounds differ from handgun and rifle rounds in three main ways.
The first is
that they are mostly plastic. Some are actually paper, but they can’t be
reloaded. More accurately, they shouldn’t be. Shotgun casings are also commonly
referred to as Hulls, and can come in a number of colors. Most 12 gauge hulls
are red. Most 20 gauge are yellow, and most 10 gauge are black. 16 and 28 gauge
are rare enough now that I can’t recall which is purple, and have no idea what
the other one is.